Thrust reversing and silencing



1366- 1958 G. B. TOWLE ET AL THRUST REVERSING AND SILENCING INVEN TOPS GEORGE 8. TOWLE RICHARD L. VASOUEZ ART UR E. WETHERBEE JR. BY 1/- A 7'TORNEY Filed April 25, 1956 United States Patent THRUST REVERSING AND SILENCING George B. Towle, Glastonbury, Richard L. Vasquez, Wethersfield, and Arthur E. Wetherbee, Jr., Newington, Conn., assignors to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Application April 25, 1956, Serial No. 580,550 8 Claims. (Cl. 60-3554) This invention relates to exhaust nozzles for jet propulsion devices and more particularly to exhaust ducts having a plurality of small nozzles for silencing purposes.

It is an object of this invention to provide a jet exhaust duct for a powerplant and comprising a plurality of small nozzles suitably arranged and means for opening and/or closing said nozzles and for reversing the flow of gases therefrom.

This and other objects of this invention will become readily apparent from the following detailed description of the drawing in which:

Fig. 1 is a perspective View of the exhaust nozzle of this invention.

Fig. 2 is a side view of the nozzle showing the reverse thrust members in their extended or operating position.

Fig. 3 is a side view of the nozzle with the elements in the afterburning position; and

Fig. 4 is a modification of the tailcone of the nozzle for afterburning.

Referring to Fig. 1, an exhaust nozzle duct is generally indicated at 10. The nozzle comprises a first axially located section generally indicated at 12 which comprises a plurality or multiplicity of small nozzles 14 which discharge exhaust gases in an aft direction. A second nozzle section is generally indicated at 16 and is spaced downstream from the nozzle section 12. This nozzle section includes a plurality of small nozzles 18 which are carried by a fixed portion of the nozzle and cooperate with one or more movable plates 20 which include a plurality of holes or passageways which cooperate with the nozzles 18. Thus in the position shown the exhaust flow from the nozzles 18 can pass through the passageways in the member 20 for discharge in an aft direction. A third nozzle section 22 is located aft of the section 16 and comprises in one modification a conical shaped fixed section which may include a plurality of nozzles as shown and described hereinafter in Fig. 3. This third nozzle section during normal operation is covered by a plurality of imperforate elements 24.

Thus as shown in Fig. 1 during normal operation exhaust gases are ejected from the nozzles 14 and 18 of the first and second sections 12 and 16 of the exhaust nozzle. Under these conditions highly efficient noise reduction is obtained with a relatively small loss in total jet thrust.

As seen in Fig. 2, the plate like elements 20 are pivoted at 28 adjacent their downstream ends and are movable to the position shown by pneumatic or hydraulic piston cyclinder combinations 30 which are carried by a fixed structure. A piston rod 32 controls a pair of links 34, 35 so as to move the plate like members 20 to the extended position shown in Fig. 2 or to the retracted position shown in Fig. 1.

Although the plate like members 20 include a plurality of passageways therein, they still contain sufiicient wall space between each of the small passageways 33 there- 2,866,316 Patented Dec. so, 1958 ICE in so that a substantial amount of reverse thrust force is provided. In other words a large portion of the gases emitted from the small nozzles 14 and 18 will be reversed to provide a braking efiect on the vehicle being powered by the particular powerplant and nozzle combination. The piston cylinder combinations 30 may be controlled in any well-known suitable manner by one or more valves or a system of valves controlled by the pilot of the aircraft.

As seen in Fig. 3 the plate like members 24 which form a cone, as shown in Fig. 1, are pivoted about their forward ends at 36 and are movable to the position shown in Fig. 3 by means of suitable piston cylinder combinations 38. The piston cylinder combinations 38 are suitably attached to a fixed portion of the nozzle section 16. in the position shown in Fig. 3' the elements 24 are open to permit gases to be emitted from a plurality of small nozzles 40 in an aft direction. In this position the maximum number of small nozzles are opened tor emission of exhaust gases as for example, during an atterburning operation of the powerplant.

Fig. 4 shows a modification or alternate arrangement of the Fig. 3 structure where additional exhaust opening is desired. Thus the aft most elements 44 and 46 in their closed position will normally discharge gases in an at't direction through the nozzles 43. however, when the elements 44, 40 are open to the position shown the exhaust gases are tree to exit through an area whose diameter is an equivalent to the diameter of the main exhaust duct at the trailing edge 48 or the second nozzle section 16a. The numeral 1611 being intended to define the member similar to that shown at 16 in Fig. 1.

As a result or this invention it is apparent that a relatively simple lightweight and highly efijcient exhaust nozzle is provided. At the same time this type of nozzle can provide normal silencing operation, or reverse thrust or atterburning. It may be desirable to have the position of the elements as shown in Fig. 3 for normal takeofi or afterburning or in a position of the elements as shown in Fig. 4. Thus the disclosed structure is capable of operating in four regimes of operation.

Although several embodiments of this invention have been illustrated and described herein, it will become apparent that various changes and modifications may be made in the construction and arrangement of the various parts without departing from the scope of this novel concept.

What it is desired by Letters Patent is:

1. An exhaust nozzle having walls extending in a downstream direction, said walls including a plurality of relatively small nozzles spaced apart for passing gases through said walls and directing them in an art direction, segmental plates symmetrically disposed about the longi- 'tudinal axis of said exhaust nozzle including pivot means for mounting said plates adjacent their downstream ends, said plates normally closely fitting a portion of said plurality of nozzles and including openings which are normally aligned with at least a portion of said plurality of nozzles, and means for pivoting said plates outwardly about their downstream ends to reverse at least a portion of the gases being emitted from the small nozzles located upstream of said downstream ends.

2. An exhaust nozzle having walls converging in a downstream direction, said converging walls including a plurality of relatively small nozzles spaced apart for passing gases through said walls and directing them in an aft direction, segmental plates symmetrically disposed about the longitudinal axis of said exhaust nozzle including pivot means for mounting said plates about their downstream ends, said plates including openings therein which are normally aligned with at least a portion of said plurality of nozzles, means for pivoting said plates outwardly about their downstream ends to reverse at least a portion of the gases being emitted from the small nozzles upstream of said downstream ends, said plates being pivoted at an axial location whereby some of said nozzles terminate in openings downstream of said location, and means for closing off the nozzles downstream of said downstream ends of said plates.

3. In an exhaust nozzle for a jet propulsion device, walls tapering in a downstream direction, said walls including a plurality of discretely distributed passages therein for emitting exhaust gases in a downstream direction and lowering the sound thereof, a first upstream section of said walls, a second section of said walls located immediately downstream of said first section, plate means cooperating with said second section and including passageways therein which are in registry with the passages in said second section when in justaposed relation there with, hinge means at the downstream end of said second section pivotally connecting said plate means to said nozzle walls, and means for moving said plate means about said hinge means to reverse at least a portion of the exhaust gases flowing from the passages in said walls upstream of said hinge means.

4. In an exhaust nozzle for a jet propulsion device, walls tapering in a downstream direction, said walls including a plurality of discretely distributed passages therein for emitting exhaust gases in a downstream direction and lowering the sound thereof, a first upstream section of said walls, a second section of said walls located immediately downstream of said first section, plate means cooperating with said second section and including passageways therein which are in registry with the passages in said second section when in juxtaposed relation therewith, said plate means being imperforate in the spaces between said passageways, hinge means at the downstream end of said second section pivotally connecting said plate means to said nozzle Walls, and means for moving said plate means about said hinge means to reverse at least a portion of the exhaust gases flowing from the passages in said walls which passages are located upstream of said hinge means, the reversal of said exhaust gases being elfected by the imperforate portion of said plate.

5. In an exhaust nozzle for a jet propulsion device, walls tapering in a downstream direction, said walls including a plurality of discretely distributed passages therein for emitting exhaust gases in a downstream direction andlowering the sound thereof, a first upstream section of said walls, a second section of said walls located immediately downstream of said first section, plate means cooperating with said second section and including passageways therein which are in registry with the passages in said second section when in juxtaposed relation therewith, hinge means at the downstream end of said second section pivotally connecting said plate means to said nozzle walls, and means for moving said plate means about said hinge means to reverse at least a portion of the exhaust gases flowing from the passages in said walls upstream of said hinge means.

6. In a exhaust nozzle for a jet propulsion device, walls tapering in a downstream direction, said walls including a plurality of discretely distributed passages therein for emitting exhaust gases in a downstream direction and lowering the sound thereof,'a first upstream section of said walls, a second section of said walls located immediately downstream of said first section, plate means cooperating with said second section and including passageways therein which are in registry with the passages in said second section when in juxtaposed relation therewith, hinge means at the downstream end of said second section pivotally connecting said plate means to said nozzle walls, means for moving said plate means about said hinge means to reverse at least a portion of the exhaust gases flowing from the passages in said walls upstream of said hinge means, a third aft section of said walls including passages therein, second plate means cooperating with said third section, and means for pivotally connecting said second plate means to said walls for movement to a position to open the passages in said third section and to a position to close the passages in said third section.

7. In an exhaust nozzle for a jet propulsion device, walls tapering in a downstream direction, said walls including a plurality of discretely distributed passages therein for emitting exhaust gases in a downstream direction and lowering the sound thereof, a first upstream section of said walls, a second section of said walls located immediately downstream of said first section, plate means cooperating with said second section and including passageways therein which are in registry with the passages in said second section when in juxtaposed relation therewith, hinge means at the downstream end of said second section pivotally connecting said plate means to said nozzle walls, means for moving said plate means about said hinge means to reverse at least a portion of the exhaust gases flowing from the passages in said walls upstream of said hinge means, a third aft section of said walls including passages therein, second plate means cooperating with said third section, and means for pivotally connecting said second plate means to said walls for movement to a position to open the passages in said third section and a position to close the passages in said third section, said second plate means including hinge means adjacent the upstream end thereof.

8. In an exhaust nozzle for a jet propulsion device, walls tapering in a downstream direction, said walls including a plurality of discretely distributed passages therein for emitting exhaust gases in a downstream direction and lowering the sound thereof, a first upstream section of said walls, a second section of said walls located immediately downstream of said first section, plate means cooperating with said second section and including passageways therein which are in registry with the passages in said second section when in juxtaposed relation therewith, hinge means at the downstream end of said second section pivotally connecting said plate means to said nozzle walls, means for moving said plate means about said hinge means to reverse at least a portion of the exhaust gases flowing from the passages in said walls upstream of said hinge means, a third nozzle section downstream of said second section including at least two elements forming a cone with the apex of the cone located downstream, passages in said sections for passing exhaust gases therethrough, and means for moving said last mentioned two elements into a non-conical open position whereby exhaust gases are emitted from said second section unrestricted.

References Cited in the file of this patent UNITED STATES PATENTS 2,024,834 Rippe Dec. 17, 1935 2,169,658 Newton Aug. 15, 1939 2,418,488 Thompson Apr. 8, 1947 2,586,788 Cushman Feb. 26, 1952 2,753,684 Greene July 10, 1956 FOREIGN PATENTS 723,160 Great Britain Feb. 2, 1955 

